Magnetic sign



M. E. WEEKS MAGNETIC SIGN March 12, 1968 Filed May 24, 1965 FIG. 2

FIG; 3

MURNIE E. WEEKS I NVEN TOR.

ATTORMEHIE United States Patent Ofiice 3,372,503 MAGNETIC SIGN Murnie E. Weeks, 16660 NE. 12th St., Bellevue, Wash. 98004 Filed May 24, 1965, Ser. No. 458,090 3 Claims. (Cl. 40-125) ABSTRACT OF THE DISCLOSURE A rigid sign adapted to be attached by magnetism to any smooth surface exposed to a rapidly moving air current and supplementing the magnetism by creating a lowpressure condition upon the underside of the sign, the magnetism being obtained from strips of a magnetic material extending continuously along the peripheral margin of the sign excepting for a break which is provided in said strip along the rear edge.

This invention relates to a magnetic sign, and for its general object aims to provide a sign which will adhere by magnetism to an unbroken foundation surface. Provided by the invention is a thin body member of flexible sheet material having or adapted to have a sign displayed upon one face and having adhesively fixed to the other face strips of a material which carries a permanent magnetic field, thus enabling the sign to be held by force of magnetism to a foundation surface composed of a material which is attracted to the magnetic field. The strips may either be parallel to but spaced from marginal edges of the sheet bodythus to leave an overhang under which a finger or fingers can be inserted for lifting the sign when it is desired to disengage same from the foundation-or the overhang may be provided along only a portion or portions of the signs perimeter and the strips placed flush with the edge along the remaining portions. These and other variations adapt the invention to sundry uses. Re-usable markers, for labelling goods stored in warehouses, and for bins carrying sorted stock, are two such uses. Another important usage is that of a removable sign for the side of an automotive vehicle in the display of an advertising message. In the mentioned two former examples the foundation surface is immobile, or relatively so, and no more than the weight of the sign and possible shock forces to which the sign or its foundation surface may become subject are factors affecting the sufiiciency of the magnetic grip.

A third factor becomes important when the sign is applied to an automotive vehicle. Little problem arises when the vehicle is operated in the lower speed ranges. However, should the vehicle be driven at higher speeds consideration must be given to the resulting increased velocity of the passing air currents and their effect upon the sign. With this third factor in mind, it is a particular object of the present invention to so design a magnetic sign, where the same is to be applied to an automotive vehicle, that air currents passing the vehicle at a high velocity will create a force which acts in complement with, rather than counter to, the magnetic pull of the magnetic strips in maintaining a grip from the foundation surface upon the sign.

With the above and yet additional objects and advantages in view, and looking to the provision of an efficient magnetic sign of simple and inexpensive construction, the invention consists in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawing:

FIG. 1 is an elevatioual view representing a commercial type of automotive vehicle with a magnetic sign em- 3,372,503 Patented Mar. 12, 1968 bodying teachings of the present invention applied to its metal-sided body.

FIG. 2 is an underside plan view of the sign drawn to an enlarged scale and representing by arrows the manner in which aerodynamic forces are employed to withdraw air from said underside of the sign so as to create a vacuum condition which augments the grip which the magnetism affords; and

FIG. 3 is a transverse vertical sectional view drawn to an enlarged scale on line 3-3 of FIG. 2.

Referring to said drawing, the body member of the sign is denoted by the numeral 10 and is composed of a sheet material, desirably metal and preferably of a gauge sufiiciently thin to permit easy flexing. The plan profile is not critical but is here shown as being rectangular. A sign is displayed upon the upper face 11 of such body member.

Strips which have a permanent magnetic field impressed thereon are adhesively secured to the underside 13 of the body member. A strip suitable for the purpose is produced by B. F. Goodrich C0., Marietta, Ohio, under the name Koroseal. One of several more or less similar products which can be used satisfactorily, Koroseal is a plastic composition capable of being easily flexed, can be securely cemented to very nearly any type of material, and is available in various widths, thicknesses, and lengths. Strips of 1" width and A thickness are suitable for labels, bin markers and other small signs. Strips of /8 thickness and /2" width are more suitable for signs of larger size. A number of adhesives available on the market are suitable for cementing the strips securely to the body member, and the strips are placed to have the same lie flush with the margins and also-between side margins-at separated intervals of the width. I find i-t desirable that the strips, denoted by 14 in the instance of the marginal or exterior strips and by 15 in the instance of the interior strips. The strips should occur at no greater intervals than 3" throughout the area of the body member, and this is to say that each interior strip 15 be separated no more than this distance from either a marginal strip 14 or another interior strip 15. The marginal strips 14 extend without break along the entire length of the front edge 16 and each of the side edges 17 and 18. Within the length of the rear edge 20 there is provided at least one and preferably two gaps 21, one lying adjacent one end and the other lying adjacent the other end of the rear edge.

In a manner which is believed to be apparent the flow of air over the exposed face and along the sides of a sign which is mounted on an automotive vehicle creates a low pressure area at the after end of the sign. Air present within the sign, or which is to say in the several connecting channels which are defined at the underside of the body member, is drawn by induction through the gaps 21 and a vacuum condition is thus produced within said channels. Tests conducted with two magnetic signs, identical excepting that the marginal strips 14 of the one extend without break throughout the entire periphery while the marginal strips of the other have gap-producing mutilations within the length of the after edge, establish that the former sign will become dislodged as the speed of the vehicle approaches 40 mph The latter sign remains firm- 1y secured even at speeds exceeding mph.

While I have here illustrated the sign as being mounted upon the planar face of a truck-type vehicle it will be understood that by reason of its flexibility the sign lends itself to usage upon the side of passenger-type vehicles where the surface to which it is applied has no abrupt irregularities. Car doors usually present a suitable surface.

It is here noted that permanently magnetized strips which are composed of plastic are superior to metal strips in that plastic-to-metal provides greater resistance to dislodgment by a shear force than does metal-to-metal.

It is belived that the invention will have been clearly understood from the foregoing detailed description of my now-preferred illustrated embodiment. Changes in the details of construction may be resorted to without departing from the spirit of the invention and it is accordingly my intention that no limitations be implied and that the hereto annexed claims be given the broadest interpretation to which the employed language fairly admits.

What I claim is:

1. The combination of a wall section composed of a paramagnetic material and having a smooth surface exposed to air currents moving at a high velocity in a prevailing direction across the same, a rigid sign overlying said exposed surface comprising a body member of thin sheet material displaying a message upon the outer face thereof and having secured to its inner face strips which carry a permanently impressed magnetic field so as to be attracted to said paramagnetic material composing the wall section, said strips extending continuously as a border along the entire peripheral margin of the body member excepting for at least one break occurring in the strip which borders the back margin of the member, thus to cause air present upon the underside of the body member to be drawn by inductive force of the passing air stream through the gap which said break produces and thereby create upon said underside a low-pressure condition augmenting the hold upon the magnetic sign which the magnetism of the strips afiords.

2. Structure according to claim 1 in which the gap lies in close proximity to a side margin of the sign.

3. Structure according to claim 1 in which two gaps are provided one located at one end extremity and the other located at the other end extremity of said back margin.

References Cited UNITED STATES PATENTS 2,639,751 5/1953 Flaherty. 3,078,183 2/1963 Karalus 40-142 3,124,501 3/1964 Wise 40-l29 LAWRENCE CHARLES, Primary Examiner. 

